There are three Charlie Chaplin films in the imdb Top 100. It seems very unfair (and more than a little boring for me), but I can see how it happened.

It happened that way because voters like me find it almost impossible to rank the films based on any modern standard. It would be unfair, of course, to compare these silent films to something dripping with special effects. In many ways, I respect the early filmmakers more for their creativity in the face of many limitations (as opposed to now, where the possibilities are almost limitless). So, we rank these films high out of respect for their historical significance rather than out of genuine enjoyment, and so they continue to thrive.